|
 |
||
      |
|
|
|
 Research & Giving News Article  In a study published in December in the Proceedings of the National Academy of Sciences, Todd Lencz, Ph.D., associate director of research at The Feinstein Institute for Medical Research in Manhasset, N.Y., and colleagues, reported evidence that schizophrenia can be inherited in a recessive manner. A recessive trait is one that is inherited from both parents. “If a person inherits identical copies of these markers from each parent, his or her risk for schizophrenia increases substantially,” said Dr. Lencz, who was the paper’s lead author. One in every 100 people suffers from schizophrenia, a condition marked by episodes of hallucinations, delusions and disordered thinking. The scientists developed a complex mathematical approach called whole genome homozygosity association (WGHA) that provides a new way of analyzing genetic information. It enables scientists simultaneously to look at genetic information derived from a patient’s mother and father, and identify pieces of chromosomes that are identical. They tested genetic material from 178 patients and 144 controls. It has been the prevailing view in psychiatric genetics that there are probably dozens, if not hundreds, of genetic variations that could lead to schizophrenia, but that each gene has a small effect. It is the wrong mix of many genes, plus unknown environmental stressors, that trigger the onset of symptoms, according to the theory. The new findings suggest another scenario, at least for a subset of patients. Dr. Lencz and his colleagues identified nine regions along the chromosomes that might play a large role in triggering the disease when two identical variants are inherited. Four of these regions contain genes that have been previously associated with schizophrenia. This can be interpreted as validation for the technique. The remaining five regions provide an additional set of newly discovered genetic risk factors. Many of the genes located in these “high-risk” regions are involved with the structure and survival of neurons. In genetic parlance, several of the markers demonstrated high penetrance, meaning that their effect on disease risk was large. In the study, 81 percent of the schizophrenia patients had at least one of these recessive markers, compared to only 45 percent of the normal control group. Nearly half of the patients had two or more, compared to 11 percent of the controls. And while no one in the healthy group had identical chunks of chromosomes in four or more of these risk regions, subjects with more than three demonstrated a 24-fold increased risk of developing schizophrenia. “This type of analysis could greatly improve our ability to diagnose schizophrenia and clarify specific subtypes of patients,” Dr. Lencz said. “The critical next step is confirming these results in independent datasets.” “What is most exciting is that the study implicates new genes in schizophrenia,” said David Goldman, M.D., chief of laboratory of neurogenetics at the National Institute on Alcohol Abuse and Alcoholism. “Now, they have to trace down the genes that mediate this vulnerability.” This story was adapted by NARSAD with permission of the Feinstein Institute. |
Media Contact
Upcoming NARSAD Events
Latest News from NARSAD
Spotlight
|
|
For the Media